Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-26T01:21:26.075Z Has data issue: false hasContentIssue false
  • English
  • Français

pH-Induced dissociation of bovine casein micelles. II. Mineral solubilization and its relation to casein release

Published online by Cambridge University Press:  01 June 2009

Douglas G. Dalgleish  and
Andrew J. R. Law
Douglas G. Dalgleish
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK
Andrew J. R. Law
Affiliation:
Hannah Research Institute, Ayr KA6 5HL, UK
Get access Rights & Permissions [Opens in a new window]

Summary

Measurements of the release of Ca, Mg and inorganic phosphate(Pi) from the casein micelles of bovine milk have been made, as functions of the pH, in the range 4·9–6·7, and at temperatures of 4, 20 and 30 °C. The results are in general agreement with earlier published studies in giving a value of 1·75–1·84 for the micellar Ca:Pi ratio. Mg appeared to behave similarly to Ca, although the amounts of micellar material were much smaller. The results on the acid-solvation of calcium phosphate are considered in relation to published quantitative studies of the pH-induced dissociation of the different types of caseins from the micelle, and of the micellar dissociation caused when micellar calcium phosphate is dissolved at neutral pH. It is evident from this that at present it is not possible to derive a universal relation between the dissociation of minerals and of caseins from the micelles at different temperatures and under different conditions.

Type
Original articles
Information
Journal of Dairy Research , Volume 56 , Issue 5 , November 1989 , pp. 727 - 735
Copyright
Copyright © Proprietors of Journal of Dairy Research 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Aoki, T., Yamada, N., Kako, Y. & Imamura, T. 1988 Dissociation during dialysis of casein aggregates cross-linked by colloidal calcium phosphate in bovine casein micelles. Journal of Dairy Research 55 189–195CrossRefGoogle Scholar
Baumy, J. J. & Brulé, G. 1988 Binding of bivalent cations to α-lactalbumin and β-lactoglobulin: effect of pH and ionic strength. Lait 68 33–48CrossRefGoogle Scholar
Chaplin, L. C. 1984 Studies on micellar calcium phosphate: composition and apparent solubility product in milk over a wide pH range. Journal of Dairy Research 51 251–257CrossRefGoogle Scholar
Dalgleish, D. G. & Law, A. J. R. 1988 pH-Induced dissociation of bovine casein micelles. I. Analysis of liberated caseins. Journal of Dairy Research 55 529–538CrossRefGoogle Scholar
Dalgeish, D. G. & Parker, T. G. 1980 Binding of calcium ions to bovine αs1-casein and precipitability of the protein–calcium ion complexes. Journal of Dairy Research 47, 113–122CrossRefGoogle Scholar
Davies, D. T. & Law, A. J. R. 1983 Variation in the protein composition of bovine casein micelles and serum casein in relation to micellar size and milk temperature. Journal of Dairy Research 50 67–75CrossRefGoogle Scholar
Davies, D. T. & White, J. C. D. 1960 The use of ultrafiltration and dialysis in isolating the aqueous phase of milk and in determining the partition of milk constituents between the aqueous and disperse phases. Journal of Dairy Research 27 171–190CrossRefGoogle Scholar
Evenhuis, N. & De Vries, Th. R. 1959 The condition of calcium phosphate in milk. VII. Netherlands Milk and Dairy Journal 13 1–15Google Scholar
Griffin, M. C. A., Lyster, R. L. J. & Price, J. C. 1988 The disaggregation of calcium-depleted casein micelles. European Journal of Biochemistry 174 339–343CrossRefGoogle ScholarPubMed
Holt, C. 1982 Inorganic constituents of milk. III. The colloidal calcium phosphate of cow's milk. Journal of Dairy Research 49 29–38CrossRefGoogle ScholarPubMed
Holt, C., Davies, D. T. & Law, A. J. R. 1986 Effects of colloidal calcium phosphate and free calcium ion concentration in the milk serum on the dissociation of bovine casein micelles. Journal of Dairy Research 53 557–572CrossRefGoogle Scholar
Holt, C., Hasnain, S. S. & Hukins, D. W. L. 1982 Structure of bovine milk calcium phosphate determined by X-ray absorption spectroscopy. Biochimica et Biophysica Acta 719 299–303CrossRefGoogle ScholarPubMed
McGann, T. C. A. & Pyne, G. T. 1960 The colloidal phosphate of milk. III. Nature of its association with casein. Journal of Dairy Research 27 403–417CrossRefGoogle Scholar
Parker, T. G. & Dalgleish, D. G. 1981 Binding of calcium ions to bovine β-casein. Journal of Dairy Research 48 71–76CrossRefGoogle ScholarPubMed
Pyne, G. T. & McGann, T. C. A. 1960 The colloidal phosphate of milk. II. Influence of citrate. Journal of Dairy Research 27 9–17CrossRefGoogle Scholar
Roefs, S. P. F. M., Walstra, P., Dalgleish, D. G. & Horne, D. S. 1985 Preliminary note on the change in casein micelles caused by acidification. Netherlands Milk and Dairy Journal 39 119–122Google Scholar
Rollema, H. & Brinkhuis, J. A. 1989 A 1H-NMR study of bovine casein micelles; influence of pH, temperature and calcium ions on micellar structure. Journal of Dairy Research 56 417–425CrossRefGoogle ScholarPubMed
Rose, D. 1968 Relation between micellar and serum casein in bovine milk. Journal of Dairy Science 51 1897–1902CrossRefGoogle Scholar
Schmidt, D. G. 1980 Colloidal aspects of casein. Netherlands Milk and Dairy Journal 34 42–64.Google Scholar
Schmidt, D. G. 1982 Association of caseins and casein micelle structure. In Developments in Dairy Chemistry – 1. Proteins pp. 61–86 (Ed. Fox, P. F.), London: Applied Science PublishersGoogle Scholar
Snoeren, T. H. M., Klok, H. J., Van Hooydonk, A. C. M. & Damman, A. J. 1984 The voluminosity of casein micelles. Milchwissenschaft 39 461–463Google Scholar
Van Hooydonk, A. C. M., Hagedoorn, H. G. & Boerrigter, I. J. 1986 pH-induced physico-chemical changes of casein micelles in milk and their effect on renneting. 1. Effects of acidification on physico-chemical properties. Netherlands Milk and Dairy Journal 40 281–296Google Scholar
Visser, J., Minihan, A., Smits, P., Tjan, S. B. & Heertje, I. 1986 Effects of pH and temperature on the milk salt system. Netherlands Milk and Dairy Journal 40 351–368Google Scholar